Installation & Operation Manual Proven Quality since 1892
ECON Hydraulic Actuator Fig.21401-21402
Rev.0
–
April, 2020
8
5
OPERATION
5.1
General Operation
The ESL/EDL
standard connection flange includes two hydraulic ports, threaded for 1/4“ BSP
couplings.
When hydraulic pressure is supplied to these ports the piston moves and slides through the housing
The actuator piston connects to the valve spindle and when operated results into an opening or closing
of the valve.
5.1.1 Double Acting actuator
When oil is supplied to port A the actuator piston will make a downwards movement(closing), when oil is
supplied to port B it will make upwards movement (opening).
5.1.2 Single Acting actuator
On a single acting actuator the opening movement is done by hydraulic pressure and the closing
movement is done by a spring.
The spring in ESL single acting actuators is of a mechanical type, the spring housing contains a set of
disc springs, whenever a spring breaks the remaining springs take over and the valve is kept close with
a slightly lower force.
5.2
Manual (emergency) operation
Besides operation through the main system, the actuator can also be operated through a handpump.
Each actuator is equipped with two Handpump connectors. In order to use these connectors, the actuator
must be isolated from the main system through pilot control valves, a ball valve, or a solenoid valve with
a closed (mid) position.
- Double acting actuators have two type QC3 connectors
- Single acting actuators have one type QC3 for pressure side and a smaller type QC5 for spring side.
Operation is the same as described before; the connector on the side of port A will close the valve,
when the connector on the side of port B will open the valve.
The QC5 connector on a single acting actuator is only used when the spring is defect.